Betsy DeVos at a hearing on Capitol Hill before the Senate Health, Education, Labor, and Pensions Committee on January 17, 2017.

By Carolyn Kaster/A.P. Images/Rex/Shutterstock.

Following an unusually rocky and contentious Senate confirmation hearing, billionaire heiress Betsy DeVos was confirmed Tuesday to lead the Department of Education after Mike Pence cast an unprecedented tie-breaking vote in her favor, marking the first time in U.S. history that the vice president was needed to tip the scales for a Cabinet nominee.

DeVos was widely pilloried by Democrats as unqualified to lead the nation’s sprawling public school system. A billionaire by marriage, DeVos rose to prominence in Republican circles as a major party donor and fierce advocate for charter schools and voucher programs. While she spent decades involved in the conservative education reform movement in Michigan, DeVos has never worked in or with public schools, nor have any of her children attended public schools. (The charter initiative DeVos championed in Michigan was generally considered a failure, with most of the schools registering below-average test scores in reading and math.)

During her Senate confirmation hearing last month, DeVos struggled to answer a series of tough questions from Democrats, who sought to highlight her inexperience for the job. DeVos flubbed a basic question about education policy from Minnesota Senator Al Franken, cited the threat of grizzly bears as justification for allowing guns in schools, expressed ambivalence about the existence of the Individuals with Disabilities in Education Act, and wouldn’t commit to not privatizing the public education system.

While secretary of education nominees have typically garnered bipartisan support, DeVos emerged as one of Trump’s most controversial Cabinet picks. Senate Democrats, backed by a legion of teachers unions, civil rights organizations and parent associations, launched a 24-hour debate that began on Monday and extended until just before the noon vote on Tuesday, during which they derided DeVos’s qualifications and cast her as an enemy of the public school system. “When presented with a nominee who says that public education is a ‘dead end’ for students in this country, people take it personally,” Connecticut Senator Chris Murphy, said in reference to a speech DeVos gave in 2015, Politico reports. “It hurts, because we all know that public schools can be better . . . but we know it’s not a dead end.”

For a brief moment, it seemed that Democrats might be able to derail DeVos’s nomination. A massive influx of constituent calls to senators’ offices, reported nationwide, convinced two Republican senators—Susan Collins of Maine and Lisa Murkowski of Alaska—to break ranks. But Democrats ultimately failed to convince a third Republican to vote no on DeVos, allowing Pence’s tie-breaking vote to secure her confirmation, with a final tally of 51 to 50.